tool_parsecfg: detect and error on recursive --config use

The config file parser now has a maximum level of inclusions allowed (5)
to detect and prevent recursive inclusions of itself leading to badness.

Bonus: clean up return code handling from the config parser.

Test 774 verifies
Closes #19168

tests/data/Makefile.am

@@ -110,7 +110,7 @@ test736 test737 test738 test739 test740 test741 test742 test743 test744 \
 test745 test746 test747 test748 test749 test750 test751 test752 test753 \
 test754 test755 test756 test757 test758 test759 test760 test761 test762 \
 test763 test764 test765 test766 test767 test768 test769 test770 test771 \
-test772 test773 \
+test772 test773 test774 \
 test780 test781 test782 test783 test784 test785 test786 test787 test788 \
 test789 test790 test791 test792 test793 test794         test796 test797 \
 \

tests/data/test2080

@@ -30,7 +30,7 @@ config file with overly long option
 <verify>
 # the used option in the config file is too long
 <errorcode>
-26
+2
 </errorcode>
 </verify>
 </testcase>

tests/data/test462

@@ -30,7 +30,7 @@ http://%HOSTIP:%HTTPPORT/%TESTNUMBER -K %LOGDIR/cmd
 # Verify data after the test has been "shot"
 <verify>
 <errorcode>
-26
+2
 </errorcode>
 </verify>
 </testcase>

tests/data/test774

@@ -0,0 +1,25 @@
+<testcase>
+<info>
+<keywords>
+--config
+</keywords>
+</info>
+
+<client>
+<name>
+config file recursively including itself
+</name>
+<file name="%LOGDIR/cmd">
+--config %LOGDIR/cmd
+</file>
+<command>
+http://%HOSTIP:%HTTPPORT/ -K %LOGDIR/cmd
+</command>
+</client>
+
+<verify>
+<errorcode>
+2
+</errorcode>
+</verify>
+</testcase>